Reliability adds value to almost all types of products. In fact, in many fields, the reliability of the various systems and sub-systems of a product may be crucial to customer satisfaction, and thus, to the success of the product on the market. In the field of aerospace products, for example, reliability may a leading factor in the capability, performance, and support costs of the product, all of which may greatly impact the product's marketability.
For example, aircraft, like most complex machines, are repairable systems whose components tend to degrade with use. Skilled pilots learn to compensate for degraded capability, nursing aircraft to achieve flight goals and successfully return to base, by taking full advantage of rich sensor data, human senses, intuition and experience. Increasing levels of automation, particularly for unmanned vehicles, result in limited operator visibility into the state of the system. This limited visibility complicates and may even exclude compensation for failure or degradation under such conditions or in harsh operating environments. Thus, although desirable results have been achieved in the reliability of aerospace products, improved abilities to assess and monitor system and sub-system status information may further improve a product's reliability.